Carton feeding mechanism



1954 1.. G. BATEMAN CARTON FEEDING MECHANISM 5 Sheets-Sheet 1 Filed Nov. 16, 1951 A m mace 48m fish-gem ATTO RNEV HHIIIIIIHIHIIHHI'IIII Dec. 7, 1954 G. BATEMAN 2,696,381

CARTON FEEDING MECHANISM Filed Nov. 16, 1951 5 Sheets-Sheet 2 Dec. 7, 1954 1.. e. BATEMAN 2,696,381

CARTON FEEDING MECHANISM Filed Nov. 16. 1 951 5 Sheets-Sheet 3 I/Zi 6 C II. will! 2 160' 1, 2 g 140 g L? a INVENTOR.

Lax/frame 6. 5472 a uye AMA/4. 1 A TTOKNE V as may hereinafter appear,

Fig. 9 is a detail in the provision of stack-advancing means for 2,696,381 CARTON FEEDING MECHANI M Application November 16, 1951, Serial No. 256,800 6 Claims. (Cl. 271-31) Lawrence G. Bateman,

This invention relates to carton-feeding mechanism.

One object of the invention is to provide a novel and improved carton-feeding machanism for feeding cartons from a stack in succession, opening the same and delivering them into pocketsof a conveyer by which the open cartons may be presented to instrumentalities for performing further operations thereon, such as for folding and sealing the bottom flaps of the cartons.

A further object of the invention is to provide novel carton-feeding me hanism of the character speci wherein provision is made for advancing the stack cartons in variable increments proportional to the thickness of one or more of the cartons being withdrawn from the stack, to the end that a substantially uniform pressure may be maintained on the stack of cartons being fed.

With these general objects in view, and such others the invention consists in the carton-feeding apparatus and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention, Figs. 1 and la represent a plan view of the present carton feeder; Fig. 2 is a side elevation of the same; Figs. 3 and 4 are plan-view details, partly in cross section, of the carton-withdrawing and opening mechanism in different positions of operation; Fig. 5 is a cross-sectional detail view of a portion of the driving mechanism as taken on the line 5-5 of Fig. 2; Fig. 6

is a front-elevat1on-detail view, partly in cross section, of the stack-advancing mechanism; Fig. 7 is a cross-sectional view taken on the line 7-7 of Fig. 6; Fig. 8 is a crosssectional detail view taken on the line 8-8 of Fig. 6, view in side elevation of a portion of the Fig. 10 is an enlarged detail mechanism shown in Fig. 6; view, partly in cross section, of ing a part of the carton-withdrawing device; and Fig. 11 is a cross-sectional view taken on-the line 11-11 of Fig. 10.

In general, the present invention contemplates cartonfeeding apparatus in which provision is made for feeding a stack of collapsed cartons into operative relation to carton-withdrawing and opening means arranged to transthe stack in their open condition into successive pockets of a conveyer which may form part the bottom flaps An important of the cartons.

feature of the present invention resides moving the stack forwardly in order to compensate for the carton blanks withdrawn from the stack and to present successive foremost cartons in the stack into operative relation to the withdrawing means. Prior to the present invention, the carton-stack advancing or compensating movement has been attempted by pawl and ratchet mechanism controlled by withdrawal of cartons from the stack, thus limiting the advancing movement to definite increments as effected by one or more teeth of the ratchet without any definite correlation between the distance thus advanced and the exact advance required by the withdrawal of one or more carton blanks. The carton stack is usually supported in a magazine, and one disadvantage resulting from the prior advancing mechanism was the possibility of an overthrow or overfeeding of the stack against the retaining elements at the forward end of the magazine so that the cartons became tightly jammed therein, thus valve mechanism form- United States Patent r 2,696,381 Patented Dec. 7, 1954 'ice preventing easy removal or free withdrawal of the foremost carton by the withdrawing device.

In accordance with the present invention, provision is made for advancing the stack in variable increments in accordance with and directly proportional to the thickness of one or more of the cartons withdrawn, whereby to maintain the forward end of the stack under a predetermined and substantially uniform pressure against the retaining elements at the forward end of the magazine and in operative relation to the withdrawing device so as to permit free withdrawal of successive foremost carton blanks from the magazine at all times.

Referring now to the drawings, in general, 10 represents a magazine arranged to support a stack of knockeddown or collapsed cartons 12 in a position to present the foremost carton in the stack in operative relation to a carton-withdrawing and opening device, indicated generally at 14. The latter is arranged to withdraw and open successive collapsed cartons from the magazine and to transfer the cartons in their open condition into successive pockets 16 defined by spaced blocks 18 attached to an endless conveyer belt 20. The conveyer belt 20 is preferably arranged to travel in a horizontal plane around a pair of spaced pulleys, one of which is indicated generally at 22, and the conveyor 20 may form part of a packaging machine of the type illustrated and described in the United States Patent No. 1,527,030 to R. D. Delemere et al., which is adapted to close and seal the bottom flaps of the carton preparatory to the filling thereof.

The carton blanks 12 may be of a well known type having a tubular body portion divided by score lines into a four-walled structure and having top and bottom closing flaps. As herein shown, the carton blanks are supported vertically with their lower edges resting upon chains 24, 26, the stack being supported laterally between guide rails 28, 30. The forward end of the stack is supported in the magazine by vertical retaining strips 32, 34 engaging the marginal side edges of the stack, and by depending bars 36 supported above the stack and engageable with the upper marginal edge thereof, as shown. Provision is made for advancing the stack along the magazine and for urging the forward end of the stack against the marginal retaining members as the cartons are withdrawn from the magazine during the operation of the machine, as will be hereinafter described.

Referring now to Figs. 1 and 2, the carton-withdrawing and opening device 14 may comprise a plurality of transfer arms 40 provided with suction cups 44, and the arms are mounted fast on a vertical rocker shaft 42. The transfer arms 40 are arranged to be rocked clockwise viewing Fig. 1 to present the suction cups .4 into engagement with the foremost carton in the stack, as shown in Fig. l, and are then rocked counterclockwise to withdraw the carton from the stack. The suction cups 44 are arranged to engage a narrow end wall 45 of the carton, and as the carton is rocked outwardly, the outer corner of the carton adjacent the opposing narrow end wall engages the face of the conveyer belt 20. The suction is then cut off, releasing the ,carton from the suction cups 44, and the slide 46 then pushes the end of the carton adjacent the end wall 45 into the position shown in Fig. 4. During this operation the carton moves from the position shown in Fig. 3 to that shown in Fig. 4, and the corner of the carton illustrated as engaging the conveyer belt 20 slides upon the belt as the latter moves until the adjacent end wall is engaged by the oncoming block 18. The slide 46 moves the carton into a position where the leading end thereof enters the space between the conveyer belt 20 and the guide rail 48 so that the continued movement of the block 18 advances the carton in its fully open position between the conveyer belt and the guide rail 48 as shown in Fig. 4. It will be understood that the conveyer belt 20 is operated continuously at a relatively high speed, and in the continued movement of the conveyer, the opened cartons are retained in their pockets 16 by the outer guide rail 48 arranged concentrically with the conveyer belt 20. The lower end of the carton may be supported by a bottom plate 50 duringthe transfer operation, and a bottom rail .52 may support the lower end of the carton in the pocket 16, as shown in Fig. 4.

42'is rotatably supported in upper and lower bearing" members 41, 43 respectively, and the mechanism for rocking the vertical shaft 42 to effect withdrawal and transfer of-successive carton blanks from the magazine 101to the pockets 16 in their open condition may comprise a gear and rack mechanism operated by an eccentric; As herein shown, the lower end of the shaft 42 is reduced in diameterand provided witha segmental gear 54 fast thereon, as illustrated in Fig. 5. A rack 56 in meshing engagement with the segmental gear is supported for reciprocation between gibs 58, 59 attached to a side frame 60 of the apparatus. The rack is pivotallyconnectedby a pin 62 to a link or strap 64 cooperating with an eccentric disk 66 fast on a continuously rotated driveshaft 68. The drive shaft may be rotated from and in timed relation to the packaging machine through connections including a chain and sprocket drive, indicated generally at70.

Suction is supplied to the transfer arms 40 through the rocker shaft 42 which is provided with an axial bore 72 communicating with the suction cups 44 through passageways 74, 76 formed in the arms 49, as shown in Figs. 3' and '4. Provision is made for controlling the suction to effect release of a carton at a predetermined time in the withdrawing and opening cycle to permit the carton to be pushed into a pocket 16 by the reciprocal slide'member 46. As shown in Figs. and 11, a reduced diameter portion at the lower end of theshaft 42 is provided with a ball bearing '78 and extends beyond the ball bearing into a closed chamber 80 formed in the bearing bracket 43 attached to the side frame 60. The chamber 80 communicates with the axial bore at the lower end of the shaft 42 and is connected by a diagonal passageway 82 with the lower end of a port 84. The upper end of the port 84 communicates with a chamber 86 formed in a slide-valve member 88. A second port 9% in communication with the valve chamber 86 comprises the suction inlet which may be connected by a pipe 92 ,to any usual or preferred source of vacuum.

The slide-valve member 38 is supported for sliding movement to effect communication with the port 84 when the member is moved to the left viewing Fig.'10,and to open the port 84 to the atmosphere when the valve member is moved to the right, and as herein shown, the valve memberSS is provided with a longitudinal slot 94 in its upper face arranged to receive the lower edge of a bar 96 secured to the rack member 56 by screws 98. In order to slide the valve member relative to the port 84,

the bar 96 is provided with valve-engaging fingers 100,

102 adjustably secured at each end of the bar by bolts 104 arranged to extend through slots 106 formed in the bar. In operation, when the rack 56 is extended or moved to the left viewing Fig. 11, the suction arms 40 are rocked into engagement with the foremost carton in the stack, and during such movement the valve member 88 is en gaged by the finger 102 and shifted to the left into position to communicate with the port 84, as illustrated in Fig. 10; During the retracting stroke of the rack, the suction arms 4t) are rocked outwardly to withdraw the foremost carton in the stack, and when the rack has moved a distance such as to rock the suction arms through approximately 90, as illustrated in Fig. 3, the finger 10 engages the valve member 88 to push it to the right a distance such as to uncover the port 84 and open the same to the atmosphere, thus releasing the carton from the suction cups 44 while the suction arms continue to rock beyond the 90 point. The port 84 will remain open to the atmosphere until the cycle is repeated and the finger 102 engages the valve member to again shift it to the left into-communication With the suction port 84.

As illustrated in Fig. 3, when the transfer armsv 40 are rocked through 90 during the withdrawing stroke, the narrow end wall 45'of the carton held by the suction cups 44 engages guide brackets 108. When the carton is pushed by the reciprocal pusher member 46 after the suction is discontinued to release the carbon from. the suction cups, the carton is guided by the bracket 108 into the space between the rail 43 and the conveyer 20. The guide brackets 1438 may comprise U-shaped plates, as viewed in Fig. 2, which are attached to the front face of the side frame 60.

The reciprocal pusher member 46 is provided with three elongated fingers 47, see Fig. 2, arranged to straddle the suction arms 40, and the. bodyportion of the 4. pusher may be adjustably secured to a slide member 110 by-bolts-112 extended through 'slots 114 formed inthe slide member. As herein shown, the slide member 110 is mounted to slide between gibs 116 attached to the side ment at substantially the same time as the rack 56 starts its retracting movement to effect withdrawal of a carton from the magazine, but the forward end of the pusher member 46 does not reach ton until the suction arms 40 are rocked outwardly substantially 90 whereupon continued movement of the pusher member 46 urges the carton along the guide membersltls andxinto the :pocket116as described. It will be understood that the withdrawing and transferring operation described is continuous and may be performed at a relatively highspeed in the'neighborhod of 240 cartons a minute.

- fromnthe back-end of the bracket 130, as sh successive carton blanks tion of the shaft 150 As illustrated in Figs. 1 and 2, the magazine 10 includes an elongated supporting bracket over which the upper-runs of the chains 24, 26 travel, being guided upon tracks 25, 27 respectively,- attached to the upper faceof the bracket 130. The guide rails 28 engaging onezside of the stack are secured to the side-frame 6t), and: rails 29 coextensive with the rails 28 may be supported at one end by brackets 31 attached to the side frame 60 andat'their other ends by a bracket 33 attached to the supporting bracket 139. The opposing guide rails 30 may be-adjustablysupported on rods 132 carried by brackets 134 attached to the supporting'bracket 130.

Provision is made for advancing the stack 12 in the magazine in variable 'incrementsin accordance with and directly proportional to the thickness of one or more Withdrawn from the magazine, and as herein shown,the'stack-supporting chains 24, 26 are: arranged torun over driven sprockets 136, 138 fast on a shaft 140 rotatably supported in bearings 142, 144 attached to the supporting bracket 130 at one mounted on a shafttlSWsupported in slots 152 in side bars 154, 156 attached to and extended rearwardly own in Fig. la. The shaft is adjustably positioned in the slots by chain-tightener rods 158 secured to collars 160 fast The rods 158 164 for adjusting the posito effecttightening of the chains. As shown in Figs. 1 and 2, a backing member 166 engaglng the rear end of the stack 12 and detachably secured to the chains 24, 26 is arranged to urge the stack forwardly-in the-magazine against the marginal retaining are provided with lock nuts the sprocket shaft 140 .is provided with a.r0ller clutch mechanism, indicated generally at 172, and which includes a circular disk 174 fast on the shaft 140,'and comprising the driven member of the clutch; a rock lever 173 comprising the driving member of the clutch and including spaced arms 175,176 pivotally mounted about the shaft 140. The lever 173' is provided With a friction plate 178 at its upper end. A cylindrical roller mounted to be capable of wedging action between the periphery of the disk 174 and the underside of the friction plate 178 to couple the driving and driven elements together when permitted to do so. As shown in' Fig. 7, the spaced arms 175, 176 of the rock lever 173 are mounted to rock on ball bearings ISZEcarried'by laterally extended'hub portions oftthe v.dislc. 174* and :are connectedcat their lower ends by bolts 184 to an extension 186. As illustrated in free condition whereby to permit easy withdrawal of sucdetail in Fig, 8, the cylindrical roller 180 is mounted be- 'cessive foremost cartons from the magazine.

tween the arms of a U-shaped retaining member 190 and In order to prevent interference with the feeler finger is resiliently urged into wedging position by a pair of 206 and associated linkage, including the clutch-disengagsprings 192 connecting the arms of the U to the rock ing member 224, when the foremost carton is being lever. The transverse leg 193 of the U may be V shaped withdrawn from the magazine, provision is made for in cross section to embrace the roller 180, as shown in clamping the linkage during a predetermined time in the Fig. 6. The rock lever 173 is arranged to be oscillated withdrawing cycle of operation, and as herein shown,

through connections to the extension 186 including a link the clamping means may include a lower stationary mem- 194 connecting the extension to a stud 196 carried by an 10 ber 226 engaging the underside of the link rod 222, and arm 198 fast on an extended portion of the eccentric stud an upper movable member 228 in yielding engagement 128, as best shown in Fig. 5, thus providing in effect a with the upper side of the rod 222 and which is arranged relatively short crank movement relative to the main to cooperate with the lower clamp to yieldingly hold the driving shaft 68 for incrementally advancing the chains entire control linkage in its clamped position during the 24, 26 through the operation of the roller clutch 172. withdrawal of a carton. The stationary clamp member In the operation of the roller clutch 172, when the 226, threaded at its lower end, may be adjustably mounted rock lever 173 is rocked in a counterclockwise direction, in a laterally extended bar 230 secured to an angle viewing Fig. 6, the roller 180, held in wedging po iti n bracket 232 adjustably attached to the side frame 60. by the springs 192, will effect rotation of the disk 174 as a h movable clamp member 228 is slidably mounted in unit with the rock lever t advan h t k, d nan L-shaped member 234 attached to and movable with versely, when the rock lever 173 is rocked in a clockwise a Vertical rod 236 Which y extend through an opening direction, the roller 180 will merely roll with relation to in the bar A compression Spring 238 Coiled about the disk 174 without effecting any rotation thereof. A the Stem 0f the pp Clamp member 228 and interposed second roller 200 is held in a stationary retainer 202 for between the head of the clamp and a portion of L-shaped cooperation with the periphery of the disk 174 and is bracket is arranged to yieldingly urge the pp clamp arranged to prevent reverse movement of the disk, as inteengagement With the pp Side Of the rod The clearly shown in Fig. 6, Th r t i 202 may b d vertical rod'2 36 18 connected at its lower end to an interto a bracket 204 attached to the side frame member 60. mediate Portion of a lever 240 p l y mounted at 242,

In practice, the stack of cartons is preferably held under e a link 244 C nne ts the lever 240 to the arm 124 forma slight compression so as to effect a substantially uniform mg a P of the pushef'aetuatlhg hnkage t p pressure against the forward end of the magazine, such eating the Pusher member as above desel'lhedas to maintain the stack in a relatively loose condition In Operation, the yieldingly Pressed PP Clamp whereby to permit easy withdrawal of successive foreh h y be maintained in an elevated pmost cartons. Provision is made for controlling the 5 lng Pesltloll y the linkage described during a major roller clutch to efiect advancement of the stack in variable 3 portion of a cycle of op and When O maintained increments so as to maintain such uniform pressure and cooperates h h l r clamp member to form a guide to prevent overcrowding or overfeeding of the stack in t0 slidiflgly pp the and during the Withthe magazine to an extent such as to interfere with easy drawing portion of the y the pp clamp member withdrawal of successive cartons by the suction-withdraw- 40 is caused to descend through the described linkage to ing device. firmly engage the rod 222 and hold it in its clamped As herein shown, the control mechanism may include position, thus rendering h n r l mechanism p a feeler finger 206 pivotally mounted at 208 and arranged iv until a r n i Withdrawn f m the m i to engage the front end of the stack, the finger being con- Thereafter, the pp Clamp member 228 is again elevated nected by a link 210 t one arm 212 f a t d; to permit the feeler finger 206 to rock against the forward lever pivotally mounted at 214. The second arm 216 is end of the stack and effect adjustment of the disengaging connected by a spring 218 to a stud 220 fixed in the side member 224 to control the amount of advance of the frame 60 so as to resiliently urge the feeler finger against stack along the magazine when the rocker arm 173 is the front end of the stack. The second arm 216 of the operated. lever is also connected by a link 222 to a roller-disengag- From the above description it will be seen that the ing member 224 slidingly mounted between the disk 174 present carton-feeding pp r is rr ng o periodand the lat 178, In ti th disengaging rnernlcal ly advance the stack of collapsed cartons in infinitively b r 224 i arranged t engage th ll 180 t h ld it variable increments within minimum and maximum limits out of wedging position between th di k 174 d th in accordance with and directly proportional to the delate 178 when the feeler finger 206 is in substantially pl of cartons from the magazine so as to m n in parallel engagem nt with th f t d f th t k, as the forward end of the stack in operative relation to the shown in Figs. 3 and 4, and when one or more -to withdrawing mechanism and to maintain a substantially blanks are withdrawn from the magazine o as to permit uniform pressure of the stack against the retaining elerocking of the f eler fing 206 inwardly or i a l kments such as to permit easy withdrawal of successive wise direction, the disengaging member 224 is retracted 0 rtol'emoet eaftOhS in the magalihe- It Will l be Seen to permit coupling engagement of the Toner 180 b t that the present variable-increment stack-advancing mechthe di k and th lat It will b b v d th t th f i anism is adapted to feed carton blanks of difierent thicktion plate 178 is arranged at right angles to a centerline IleSSeS d to ffect advancement of the stack to compendrawn through th di k 174 d i Spaced f th di k sate for variable thicknesses without the necessity of makso that wedging engagement of the roller 180 occurs at mg y adjustment interchange of Operating P a predetermined point between the disk and the plate. While the preferred embodiment of the invention has With this construction it will be seen that a relatively been herein illustrated and described, it will be undersmall inward rocking movement of the feeler finger 206 stood that the invention may be embodied in other forms will retract the disengaging member 224 only slightly so W hi t s pe f th foll Wiflg claims. that during the initial portion of the full stroke of the Having thus described the invention, what is claimed rock lever 173 in a counterclockwise direction, the roller i 180 is held out of wedging engagement, and during the l. Carton-feeding apparatus having, in combination, latter part of the stroke of the rock lever, the roller is means for supporting a stack of cartons, means for withengaged between the disk and the plate at a point beyond drawing successive foremost cartons from the stack, means the influence of the disengaging member 224 to effect an for periodically advancing the stack to move successive advance of the stack through a relatively small increment foremost cartons into operative relation to the cartondirectly proportional to the rocking moveme of th withdrawing means, and control means including means feeler finger 206. engageable with the carton being withdrawn and re- In this manner, the stack may be advanced periodically sponsive to the withdrawal of cartons from the stack and through either a full stroke or a partial stroke in accordoperatively connected to said advancing means for varying ance with the rocking movement of the feeler finger 206 the advancing movement in accordance with and directly to maintain the forward end of the stack against the proportional to the thickness of the individual cartons retaining members 32, 34 and 36 in operative relation withdrawn from the stack, said advancing means includto the withdrawing device and with a substantially uniform ing a roller clutch, and means for oscillating said clutch pressure such as to maintain the cartons in a relatively through a fixed stroke, said control means further including a disengaging member movableinto different positions relative to the stroke of said roller clutch for varying the effective advancing stroke.

2. Carton-feeding apparatus having, in combination, means for supporting a stack of cartons, means for Withdrawing successive foremost cartons from the stack, means forperiodically advancing the stack to move successive foremost cartons into operative relation to the cartonwithdrawing means, and control means including means engageable with the carton being withdrawn and responsive to the Withdrawal of cartons from the stack and operatively connected to said advancing means for varying the advancing movement in accordance with and directly proportional to the thickness of the individual cartons withdrawn from the stack, said advancing means including a roller clutch, and means for oscillating said clutch through a fixed stroke, said control means further including a disengaging member movable into different positions relative to the stroke of said roller clutch for varying the effective advancing stroke, and means for clamping said control means to preventinterference with and movement of said disengaging member during the withdrawal of a carton from the stack.

3. Carton-feeding apparatus having, in combination, a magazine for supporting a stack of cartons, retaining elements cooperating with opposed marginal portions of the front of the stack, a movable backing member engageable with the other end of the stack, suction means for Withdrawing successive foremost cartons from the stack'and out of said retaining elements, means operatively connected to said backing member for periodically advancing the stack against said retaining elements to move successive foremost cartons'into operative relation to the carton-withdrawing means, said advancing means including a roller clutch, means for oscillating the clutch through a fixed stroke, control means including a feeler finger movable into engagement with successive foremost cartons in the stack, and a roller disengaging member operatively connected to and movable with said feeler finger, said disengaging'member being movable into different positions relative to said stroke to vary theelfective advancing stroke through different increments directly proportional to the movement of said finger in response to the withdrawal of cartons from the stack whereby to prevent overcrowding of the cartons against the retaining elements and to permit easy withdrawal of successive foremost cartons from the stack.

4. Carton-feeding apparatus having, in combination, a-magazine for supporting a stack of cartons, retaining elements cooperating with opposed marginal portions of thefront of the stack, a movable backing member engageable with the other end of the stack, suction means for withdrawing successive foremost cartons from the stack and out of said retaining elements, means operatively connected to said backing member for periodically advancing the stack against said retaining elements to move successive foremost cartons into operative relation to the carton-withdrawing means, said advancing means including a roller clutch, means for oscillating the clutch through a fixed stroke, control means includinga feeler finger movable into engagement with successive foremost cartons in the stack, and a roller disengaging member operatively connected to and movable with said feeler finger, said disengaging member being movable into different positions relative to said stroke to-vary the effective advancing stroke through different increments directly proportional to the movement of said stack whereby to prevent overcrowding of the cartons against the retaining elements and to permit easy withdrawal of successive foremost cartons from the stack, and means for locking said control means to prevent movement of said feeler finger and said disengaging member during the Withdrawal of a carton from the stacrt.

5. in apparatus of the character described, in combination, means for supporting a stack of articles to be fed, means for withdrawing successive foremost articles from the stack, and means for incrementally advancing the stack to move successive foremost articles into operative relation to the withdrawing means, said advancing means including a roller clutch having a driving memher, a driven member and a roller coupling member, means for oscillating said driving member through a fixed stroke each cycle of operation, and control means including a pivoted finger yieldingly engageable with successive foremost articles in the stack, and a clutchdisengaging member connected to said finger and to said roller, said disengaging member being movable to engage said roller at different positions relative to said fixed stroke to variably limit the effective advancing stroke through different increments directly proportional to the movement of said feeler finger in response to Withdrawal of an article from the stack.

In apparatus of the character described, in combination, means for supporting a stack of articles to be fed, means for withdrawing successive foremost articles from the stack, and means for incrementally advancing the stack to move successive foremost articles into operative relation to the withdrawing means, said advancing means including a roller clutch having a driving member, a driven member and a roller coupling member, means for oscillating said driving member through a fixed stroke each cycle of operation, and control means including a pivoted finger yieldingly engageable With successive foremost articles in the'stack, and a clutchdisengaging member connected to said finger and to said roller, said disengaging member being movable to engage said roller at diiferent positions relative to said fixed stroke to variably limit the effective advancing stroke through different increments directly proportional to the movement of said feeler finger in response to withdrawal of an article from the stack, and means for clamping said control means to prevent interference with said feeler finger and said disengaging member during the withdrawal of an article from the stack.

References Qited in the file of this patent 

